Integrated Circuits are typically packaged in multi-pin, square packages wherein equal numbers of electrical connections reside on all four sides of the package. Several factors influence how the pins of the respective differential input and output pairs are assigned. These include optimizing data flow patterns, minimizing transmission line impedance discontinuities and signal crosstalk. The last two are to assure signal integrity.
Data is transmitted and received electrically through various media such as coax cables, twisted pair lines and printed circuit transmission lines. Unwanted electrical coupling, generally known as cross coupling, between the transmitter and receiver inputs and outputs becomes more of a problem as data rates increase and package size decreases.
A combined transmitter and receiver function is known as a transceiver. Multiple receivers or transmitters can also be integrated in a single package to facilitate data transmission. Other products such as a cross-point switch can be used in a special configuration to achieve this transceiver function. A traditional cross-point switch allows any input to be directed to any single or combination of multiple outputs. The basic structure of a traditional cross-point switch is set forth in FIG. 1.
Accordingly, what is needed is a pinout capable of dual configuration of data flow to operate as a dual receiver or transmitter, or as a transceiver so as to improve signal integrity and provide greater user flexibility.